The present invention relates generally to golf club heads, and is particularly concerned with the provision of adjustable weighting in a golf club head.
Golf clubs are generally divided into four main types, comprising putters, irons, fairway clubs and drivers. Drivers in the past were normally made of wood, and so were normally referred to as "woods." More recently, such drivers have been made of metal, normally investment cast stainless steel, and are often referred to as "metal woods." Each category of golf club is made in a range of different sizes and weights to accommodate different player's requirements and playing conditions.
One important factor in determining performance of any type of golf club is the distribution of weight around the head while providing the correct total weight for that particular club. Weight distribution about the head will control the position of the center of gravity of the club and is considered to control the position and size of the so-called "sweet spot," or the area on the front or ball striking face of the club on which the ball should be struck to produce the 'most accurate results. Thus, it is often considered desirable to add weight at the heel and toe, for example, in order to produce a larger sweet spot.
Various weighting arrangements have been proposed in the past in order to provide the desired weight distribution and to vary the weight distribution between different clubs in order to accommodate different player's requirements, e.g. beginning golfers or professionals. In some cases, weighted inserts are embedded in the head at appropriate positions to provide the desired weight distribution, for example as described in U.S. Pat. No. 3,995,865 of Cochran et al., or by adding lead powder in a foam filling to the central cavity of a hollow club head. Some heads have internal cavities in which weights such as lead slugs may be placed in order to suit the needs of different golfers. Where the cavity is accessible, for example via a removable sole or crown plate, the same club may be adjusted for different golfers. In U.S. Pat. No. 3,976,299 of Lawrence et al., adjustable weights or plugs are disposed adjacent the face of the club head in tapped apertures extending through the sole of the club head. The plugs may be moved along the length of the aperture in order to adjust weight distribution. In other clubs, lead or brass weights are secured at the end of the club shaft to bring the club to the desired swing weight.